Erronous import failure message

[dakhnod]

Version

v20.10.0 up to v22.4.1

Platform

Linux dakhnod 6.5.0-10043-tuxedo #47 SMP PREEMPT_DYNAMIC Tue Jun  4 14:29:55 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

1. run npm install is-odd
2. delete node_modules/is-odd/index.js
3. start node
4. run await import("is-odd")
   -> Should yield this message:

Uncaught:
Error: Cannot find package '/app/node_modules/is-odd/package.json' imported from /app/repl
    at legacyMainResolve (node:internal/modules/esm/resolve:210:26)
    at packageResolve (node:internal/modules/esm/resolve:829:14)
    at moduleResolve (node:internal/modules/esm/resolve:915:18)
    at defaultResolve (node:internal/modules/esm/resolve:1132:11)
    at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:557:12)
    at ModuleLoader.resolve (node:internal/modules/esm/loader:526:25)
    at ModuleLoader.getModuleJob (node:internal/modules/esm/loader:249:38)
    at onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:484:36)
    at TracingChannel.tracePromise (node:diagnostics_channel:337:14) {
  code: 'ERR_MODULE_NOT_FOUND'
}

complaining about not being able to find package.json, although that file exists.
What is really missing is index.js, since we deleted it.

How often does it reproduce? Is there a required condition?

always

What is the expected behavior? Why is that the expected behavior?

It would help if node reported about the really missing index.js, not the existing package.json

What do you see instead?

Node complains about not being able to find package.json, although that one clearly exists.

Additional information

No response

[avivkeller]

Two questions:

Does this also occur with require?
Is this REPL specific, or does it occur with files?

[dakhnod]

> const odd = require ('is-odd');
Uncaught:
Error: Cannot find module '/app/node_modules/is-odd/index.js'. Please verify that the package.json has a valid "main" entry
    at tryPackage (node:internal/modules/cjs/loader:482:19)
    at Module._findPath (node:internal/modules/cjs/loader:765:18)
    at Module._resolveFilename (node:internal/modules/cjs/loader:1205:27)
    at Module._load (node:internal/modules/cjs/loader:1045:27)
    at TracingChannel.traceSync (node:diagnostics_channel:315:14)
    at wrapModuleLoad (node:internal/modules/cjs/loader:215:24)
    at Module.require (node:internal/modules/cjs/loader:1304:12)
    at require (node:internal/modules/helpers:123:16) {
  code: 'MODULE_NOT_FOUND',
  path: '/app/node_modules/is-odd/package.json',
  requestPath: 'is-odd'
}

require works properly.

Yep, also occurs in files:

root@18f9f8c95d94:/app# node app.mjs 
node:internal/modules/esm/resolve:210
  const resolvedOption = FSLegacyMainResolve(packageJsonUrlString, packageConfig.main, baseStringified);
                         ^

Error: Cannot find package '/app/node_modules/is-odd/package.json' imported from /app/app.mjs
    at legacyMainResolve (node:internal/modules/esm/resolve:210:26)
    at packageResolve (node:internal/modules/esm/resolve:829:14)
    at moduleResolve (node:internal/modules/esm/resolve:915:18)
    at defaultResolve (node:internal/modules/esm/resolve:1132:11)
    at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:557:12)
    at ModuleLoader.resolve (node:internal/modules/esm/loader:526:25)
    at ModuleLoader.getModuleJob (node:internal/modules/esm/loader:249:38)
    at onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:484:36)
    at TracingChannel.tracePromise (node:diagnostics_channel:337:14)
    at ModuleLoader.import (node:internal/modules/esm/loader:483:21) {
  code: 'ERR_MODULE_NOT_FOUND'
}

Node.js v22.4.1

[avivkeller]

I'm not able to reproduce
screen-capture.webm

[dakhnod]

you need to delete the index.js

[avivkeller]

Oh, okay

[avivkeller]

+ repro-exists:

$ npm i is-odd

added 2 packages in 329ms
                                                                                                                                                                                                                               
$ rm node_modules/is-odd/index.js    
                                                                                                                                                                                                                               
$ node        
Welcome to Node.js v22.4.1.
Type ".help" for more information.
> await import('is-odd')
Uncaught:
Error: Cannot find package '/node_modules/is-odd/package.json' imported from /repl
    at legacyMainResolve (node:internal/modules/esm/resolve:210:26)
    at packageResolve (node:internal/modules/esm/resolve:829:14)
    at moduleResolve (node:internal/modules/esm/resolve:915:18)
    at defaultResolve (node:internal/modules/esm/resolve:1132:11)
    at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:557:12)
    at ModuleLoader.resolve (node:internal/modules/esm/loader:526:25)
    at ModuleLoader.getModuleJob (node:internal/modules/esm/loader:249:38)
    at onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:484:36)
    at TracingChannel.tracePromise (node:diagnostics_channel:337:14) {
  code: 'ERR_MODULE_NOT_FOUND'
}
> 

[dakhnod]

So...does this confirm my description?

[avivkeller]

Yup :-)

[targos]

@nodejs/loaders

[targos]

Note that the message was never precisely correct in ESM.
Behavior changed between Node.js 20.4.0 and 20.5.0.

In v20.4.0, the message was:

Error [ERR_MODULE_NOT_FOUND]: Cannot find package '/XXX/node_modules/is-odd/' imported from /XXX/test.js

[marco-ippolito]

I believe this is an edge case that has not been covered.
This might be the commit that might have introduced it a2a8e31, released in Node v20.5.0
cc @H4ad

[H4ad]

I forgot to translate correctly the path fileURLToPath(new URL('.', packageJSONUrl)), fileURLToPath(base)).

I will try open a PR soon.